Chemotherapeutic agents for the control of plant diseases

ABSTRACT

A chemotherapeutic composition for the control of plant diseases caused by mycoplasma-like organisms, rickettsia-like organisms, or seed-borne legume viruses. The composition is composed essentially of the tannate complex of picro ammonium formate combined with a minor amount of a surfactant sufficient to prevent formation of ammonium picrate. The preparation and use of the composition are disclosed. Also disclosed is a related chemotherapeutic composition for the control of plant diseases caused by plant pathogenic fungi and bacteria and composed essentially of a tannate complex of picro cupric ammonium formate in aqueous solution combined with a minor amount of a surfactant sufficient to prevent formation of ammonium picrate, along with its method of preparation and manner of use.

FIELD OF THE INVENTION

This invention relates broadly to the field of chemotherapeutic controlof plant and animal diseases caused by certain organisms.

BACKGROUND OF THE INVENTION

One aspect of this invention relates to the chemotherapeutic control ofplant diseases caused by a group of organisms termed mycoplasma-likeorganisms (MLO) and rickettsia-like organisms (RLO) with a novelchemotherapeutic agent designated KT-198. KT-198 is a tannate complex ofpicro ammonium formate combined with a minor amount of a surfactantsufficient to prevent formation of ammonium picrates. Both MLO and RLOwere previously thought to be viruses since they pass through filtersthat hold back bacteria and could not be detected by ordinary lightmicroscope. With the development of electron microscopy and newmicrobiological techniques, these have been shown to be organisms whichcould be cultivated on special nutrient media, and at least for some ofthem Koch's postulates have been established. The RLO are walledorganisms and inhabit xylem or phloem cells depending on the speciesconcerned. Some of the serious diseases of plants such as phony peach,Pierce's diseases of grapes, citrus greening and die-back, grassy shootof sugar cane, etc. are examples of RLO diseases.

More than 50 diseases of plants at one time considered to be of viralorigin have now been shown to be mycoplasmas (including the motileSpiroplasma). Very important plant diseases such as elm phloem necrosis,yellow lethal wilt of coconut, sandal spike disease, X-disease of peach,pear decline, potato witches broom, corn stunt, yellow dwarf of rice,aster yellows, mulberry dwarf, etc. have been shown to be of MLO origin.More and more examples are being found. Another group of diseases forwhich the chemotherapeutant of the present invention, KT-198, has beendeveloped is against some of the legume viruses which are seed-borne.

Another aspect of this invention relates to the chemotherapeutic controlof plant diseases where the causal organisms are plant pathogenic fungiand bacteria with another novel chemotherapeutic agent of this inventiondesignated KT-19827. KT-19827 is a tannate complex of picro cupricammonium formate in aqueous solution combined with a minor amount of asurfactant sufficient to prevent formation of ammonium picrate.

This new chemotherapeutic agent is useful in the control of thefollowing types of diseases and similar plant diseases:

(1) Internally and externally seed-borne fungal and bacterial diseasesof plants.

(2) Downy mildew and powdery mildews of plants caused by fungi.

(3) Root rots and wilt diseases of plants where the organisms aresoil-borne, and where many of the conventional fungicides cannot be usedsince they affect the living root system.

(4) Systemically infected trees where the fungus is in the vasculartissues and only those systemic fungicides which when injected aretranslocated inside the vascular strands can be used. As examples, theoak wilt disease and the Dutch elm disease, both caused by differentspecies of the fungus Ceratocystis. These diseases have remained"incurable" up to the present time. The present novel fungicide is thefirst of its kind which has proved effective in more than 900 treatedtrees, effectively controlling the disease.

(5) A large number of plant bacterial diseases incited by species of thegenus Xanthomonas, Pseudomonas, Erwinia and Corynebacterium, which up tothe present were controlled chiefly by the use of antibiotics such asstreptomycin and tetracyclines or their combination. Due to thedevelopment of antibiotic resistant bacterial strains, such diseaseshave no direct control measures now. No really effective bactericide isyet available though partial effect has been claimed with manycompounds. The novel bactericide of this invention offers the firsteffective control of phytopathogenic bacterial pathogens, both as seedtreatment, plant dips and spray schedules.

THE PRIOR ART

In both RLO and MLO diseases, the only means of control has beentreating the plants by injections or spray schedules with tetracyclines.These bring about temporary regression of the symptoms, which, however,reappear after some time.

There are very few antiviral chemotherapeutants known for control ofanimal viruses, and much less for plant viruses. Among a few of theclinically used chemotherapeutants against DNA animal viruses, mentionmay be made of idoxuredine, arabino-furanosylcytosine,arabino-furanosyladenine, methisazone and 6-azauredine. Some of thechemotherapeutants against oncogenic viruses include cyclohexamide,noformacin, ribavirin, dimethylbenzylrifampicin, etc.

Of particular interest in the development of antiviral substances whichhas direct bearing on the present chemotherapeutant, KT-198, is the mostrecent discovery of trisodium phosphoformate as an effective antiviralagent in vivo against cutaneous herpes-virus infection in guinea pigs(Stefan Alenius, Zvonimir Dinter, and Bo Oberg, in Antimicrobial Agentsand Chemotherapy, September 1978, 408-413). It may be pointed out thatnone of the above known chemotherapeutic agents are active against plantviruses and none are known to be controlling of mycoplasma-likeorganisms or rickettsia-like organisms causing plant diseases.

Among compounds used as fungicides, bactericides and anti-fouling agents(including killing of algae), copper compounds are well known andnumerous patents have been granted for their use. These copper compoundscan be grouped under two headings:

(1) WATER SOLUBLE COPPER COMPOUNDS--All soluble copper compounds arehighly toxic to the living plants and are used only on dead materialssuch as cellulose fibers, as components of wood preservatives,anti-fouling agents where the intention is killing the polluting agents,like algae in ponds, etc. When used on living plant tissue, they showhigh phyto-toxicity, burn and kill the plants. The soluble coppercompounds previously used include (a) cupric sulphate, (b) cupricacetate, (c) cupric chloride and cupric chlorate, (d) cupric formate,also called Tubercuprose, (e) cupric hexafluorosilicate, (f) cupricnitrate, (g) cupric chromate (used in preventing growth of fungi andbacteria infesting cellulose fibers), and (h) cupric ammonium complex.

(2) WATER INSOLUBLE COPPER COMPOUNDS--All copper fungicides used atpresent are water insoluble complexes, and form deposits on the treatedparts as colloidal layers. When the fungus spore germinates on thesurface, soluble copper is released and the fungus is killed. In brief,none of the presently existing fungicides is absorbed and translocatedwithin the plant tissue without killing is host cells as well as killingthe fungal or bacterial pathogen.

SUMMARY OF THE INVENTION

Broadly stated, the chemotherapeutic agent designated KT-198, is atannate complex of picro ammonium formate combined with a minor amountof a surfactant sufficient to prevent formation of ammonium picrate. Thepicro ammonium formate is produced without the concurrent production ofammonium picrate by reacting picric acid (2,4,6trinitrophenol) withammonium formate in a viscid solution of ammonium formate containing asurfactant, such as an alkali metal alkyl sulphate in amount sufficientto prevent formation of ammonium picrate, and combining with tannicacid. For each 100 parts by dry weight of ammonium formate in thecomplex, picric acid is present in amount between about 2 to 5 parts byweight, tannic acid is present in amount between about 0.5 to 2 parts byweight, and the surfactant is present in amount between about 2 to 10parts by weight.

Broadly stated, the fungicide and bactericide designated KT-19827 is atannate complex of picro cupric ammonium formate in aqueous solutioncombined with a minor amount of a surfactant sufficient to preventseparation of ammonium picrate. The complex is produced by reactingcupric sulphate with ammonium formate, combining with tannic acid andcomplexing with picric acid, in aqueous solution containing a minoramount of a surfactant sufficient to prevent separating out of thetannate complex. One mole of a water soluble cupric salt, such as cupricsulphate, is reacted with a stoichiometric equivalent of 2 moles ofammonium formate, or with a stoichiometric excess of 15 to 45 percent byweight of ammonium formate and this product is complexed with picricacid. For each 100 parts by dry weight of cupric ammonium formate,picric acid is added in amount between about 2 and 5 parts by weight,surfactant is added in amount between about 2 to 10 parts by weight andtannic acid is added in amount between about 0.5 to 3.5 parts by weight.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A. PRODUCTION OF KT-198

The present chemotherapeutant, KT-198, is a tannate complex of picroammonium formate combined with a minor amount of a surfactant sufficientto prevent formation of ammonium picrate. KT-198 is a highly watersoluble stable compound and relatively non-toxic to animals and plantsat doses used to control the diseases under consideration.

According to the present invention, in the process for the production ofKT-198, ammonium formate is dissolved in water to which known amounts ofa surfactant and tannic acid are added. The mixture is warmed on a waterbath at 60° C. and this results in formation of a viscid solution. Whensolid picric acid in known quantity is added, it goes into solutionafter considerable lapse of time, depending upon the quantity handledand physical conditions, such as agitation, etc. There is no formationof precipitate of ammonium picrate as in the case of direct addition ofpicric acid to an ammonium formate solution. All the picric acid goesinto solution with the formation of picro ammonium formate, and, withsodium lauryl sulphate as the surfactant and tannic acid, there isproduced the tannate complex of picro ammonium formate. The KT-198 is adark brownish-yellow material which is very stable, and completelysoluble in water to produce a golden-yellow solution.

With this as the background, the following details for the preparationof KT-198 are described below.

Example A-1

The following details of preparation are followed for producing aboutone kilogram of KT-198: 800 grams of ammonium formate are added to 400cc of water; 80 grams of sodium lauryl sulphate and 40 grams of tannicacid are added to the solution and warmed on water bath at 60° C. for 30minutes. The mixture is well agitated, and cooled to room temperature(24° C.) and 40 grams of picric acid are added and well shaken. Thepicric acid settles down mostly at the bottom, and as it slowlydissolves over a period of 6 to 24 hours, the entire mass turnsuniformly brownish-yellow. The mixture is kept at 50° to 60° C. whichmakes the reaction complete and also evaporates the water. Water may befurther evaporated in a vacuum oven at 35° to 40° C. The resulting drypowder may be stored as such or formulated for use in plant diseasecontrol.

Example A-2

According to an alternate method of preparing KT-198, 40 grams of sodiumlauryl sulphate and 20 grams of tannic acid are dissolved in 200 cc ofwater containing 400 grams of ammonium formate prior to the addition of20 grams of picric acid in 500 cc propylene glycol, all at roomtemperature. The tannate complex of picric ammonium formate is producedand there is no dissociation and separating out of ammonium picrate,whose solubility in water is low (1 gram in 100 cc of H₂ O at 20° C.)and readily separates out. The role of sodium lauryl sulphate additionto ammonium formate prior to reaction with picric acid, is to preventformation of ammonium picrate.

B. PRODUCTION OF KT-19827

The chemotherapeutic, KT-19827, is a tannate complex of picro cupricammonium formate in aqueous solution combined with a minor amount of asurfactant sufficient to prevent separating out of the tannate complex.KT-19827 is a soluble complex and is also relatively non-toxic toanimals and plants at doses used to control bacterial and fungal plantdiseases, and viral and mycoplasma diseases also previously mentioned ascontrolled by KT-198.

Cupric ammonium formate CuNH₄ (HCOO)₂ is produced when one mole ofcupric sulphate is reacted with 2 moles of ammonium formate in aqueousmedium. Tannic acid addition to this results in formation of the tannatecomplex, which is water soluble gradually dissociating into waterinsoluble cupric tannate. It has been pointed out by studies of A. W.Davidson and Vernon Holm (Journal of American Chemical Society53:1350-1357, 1931) that the solubility of cupric ammonium formateincreases with excess addition of ammonium formate up to 43.75 molepercent. There is no solid phase separating out, and on slight warming adeep violet bluish solution is formed. A ternary system NH₄ CHO₂--Cu(CHO₂)₂ --HCHO₂ is formed. While this resembles cupric ammoniatesolution formed by addition of excess of ammonia to cupric sulphatesolution, the presence of the formate in the complex makes it totallydifferent. The avidity of picric acid to form complexes with copperammoniates is well known. Joshi and Bhargava (Journal of Indian ChemicalSociety 40:19-22, 1963; Chemical Abstracts, 58:13408 d, 1963) showedthat when picric acid is added to a cupric ammoniacal solution, an olivegreen precipitate is formed which by spectrophotometric study showedthat the picric acid copper ammoniate complex had one part of Cu(NH₃)₄++ and 2 parts of picric acid. N. P. Agafoshin (Chemical Abstracts32:72, 1938) reported that complex compounds of picric acid with copperammoniates are formed when aqueous solutions of picric acid are added toNH₄ OH solution of Cu(OH)₂. A precipitate of the complex is formed withthe formula [(C₆ H₂ (NO₂)₂ O)]₂ --(CuNH₂)₄.

A similar complex is formed when picric acid is reacted with cupricammonium formate solution. However, unlike cupric ammoniate solution,there is no formation of precipitate, but a soluble complex.

The physical properties of the product also show the formation of thenew complex, KT-19827. Cupric sulphate has no melting point butdecomposes at 560° C. and above. Ammonium formate has a melting point of116° C. When cupric ammonium formate complex is produced and evaporatedto dryness, a hard bluish material is formed, which will not melt evenwhen autoclaved at 120° C. After the formation of the picrate complex ofcupric ammonium formate, the product melts at 60° C. and can be handledas a thick viscid liquid. Hence, the KT-19827 fungicide-bactericide canbe constituted in any formulation. A water-soluble tannate complex ofpicro-cupric ammonium formate is formed. The product is a greenish-brownto olive-green material which on dissolving in water forms a paleyellowish-brown solution with fungicidal and bactericidal properties.

The details for the production of KT-19827 are described below.

Example B-1

20 grams of tannic acid is dissolved in 200 ccs of water to which 400grams of pure (technical grade) ammonium formate is added and thesolution is warmed up to 70° C. 400 grams of copper sulphate,pentahydrate, is powdered and added and mixed thoroughly. 40 grams ofsodium lauryl sulphate is added and thoroughly mixed. 20 grams of picricacid is added, thoroughly mixed and dried in a vacuum oven at 40° C. Apasty greenish-black water soluble mass is produced which can be storedat room temperature for long periods. 250 grams of the KT-19827 thusproduced is weighed and titurated with 500 ccs of commercialnon-phosphate dishwashing detergent or propylene glycol. The wholemixture forms a viscid mass, which can be dispensed to containers inmeasured quantities for dilution and use in the field.

Example B-2

800 grams of ammonium formate is added to 400 ccs of water. 80 grams ofsodium lauryl sulphate and 40 grams of tannic acid are added and warmedon water bath at 60° C. for 30 minutes. The mixture is well agitated,and cooled to room temperature (24° C.). 800 grams of powdered cupricsulphate is added, and 40 grams of picric acid dissolved in 500 cc ofpropylene glycol is added and well shaken. The picric acid settles downmostly at the bottom, and as it slowly dissolves over a period of 6 to24 hours, the entire mass turns uniformly brownish-yellow.

That stoichiometrically equivalent amounts of ammonium formate to cupricsulphate may be used is illustrated by the following.

Example B-3

126 grams of ammonium formate (M. W. 63) is dissolved in 200 ccs ofwater containing 10 grams of tannic acid. 159 grams of cupric sulphate(anhydrous) (M. W. 159.6) is added, and warmed on a water bath at 60° C.until a clear deep blue solution is formed. 20 grams of sodium laurylsulphate is now added and the mixture agitated until all the sodiumlauryl sulphate dissolves. A deep greenish-blue solution is formed. 10grams of picric acid is dissolved in 500 ml of commercial non-phosphatedishwashing detergent or propylene glycol. The picric acid dissolvesslowly and forms a complete solution with no precipitate. This solutionis added slowly to the solution above and mixed well.

Example B-4

20 grams of tannic acid is dissolved in 200 ccs of water. 252 grams ofammonium formate are added and dissolved. 40 grams of sodium laurylsulphate is added, and the solution containing tannic acid, ammoniumformate and sodium lauryl sulphate is warmed on a water bath 60° C. for15 minutes. 318 grams of anhydrous cupric sulphate is added and agitateduntil a homogenous thick solution is formed. 250 ccs of commercialnon-phosphate dishwashing detergent or propylene glycol, is added to theabove, and this makes the cupric ammonium formate double salt complex oftannic acid with sodium lauryl sulphate, as a homogenous product. 20grams of picric acid is added to 500 ccs of commercial non-phosphatedishwashing detergent or propylene glycol, and allowed to stand untilall picric acid goes into solution. This solution is added to thesolution above and mixed well. A partly water soluble tannate complex ofpicric ammonium formate is formed.

The presence of a surfactant in KT-198 and KT-19827 serves severalpurposes. The surfactant acts as a spreader when the chemotherapeuticagent is sprayed. It also enhances the diffusion of the agent intoremote pockets within the plant when plant injections with the agent aremade. Other surfactants may be used in KT-19827, such as other alkalimetal alkyl sulphates.

The role of picric acid is as a mordant on the walls of the pathogenswhich then in the case of KT-19827 permits greater penetration.Penetration of the copper complex through the pathogen walls and theplant cell walls is enhanced by it being complexed with the ammoniumformate into a more soluble ionizable form.

The effect of tannic acid addition in KT-19827 is antidotingphytotoxicity of copper.

C. CHEMOTHERAPEUTIC USE OF KT-198

The following examples illustrate the use of KT-198 in controlling plantand animal diseases. For example, the chemotherapeutant KT-198 may beformulated in glycerine only, or a mixture of glycerine and a watermiscible solvent like methyl cellosolve mixed in equal quantities onvolume bases. In control of plant diseases, KT-198 may be formulated inany agriculturally acceptable, non-toxic carrier.

Example C-1

Elm phloem necrosis is a serious wilt disease of elms in the UnitedStates caused by a mycoplasma-like organism. The progress of the diseasesymptoms extends over several years, from yellowing die-back of shootsto final wilting.

Experiments were carried out to determine the effectiveness of KT-198 incontrolling the elm phloem necrosis. Five grams of KT-198 dissolved in agallon of water (about 0.0013%) was pressure injected into the trunks often trees during the months of August-September, using the Reil pressureinjection apparatus. Four untreated trees served as controls and eighttrees treated with Terramycin, a tetracycline, served as a comparison ofa prior art treatment. In October of the next year, results showed thatKT-198 was superior to tetracycline. 75 percent of the untreated treesdied. 60 percent of tetracycline treated trees died. None of KT-198treated trees died.

    __________________________________________________________________________                                   Total amt, in-                                 Symptom at time of             jected in gms.                                 injection        Size of Elm   (no. in paren-                                                                              Condition of                          % Necrotic  (diameter in  thesis is no. Elm tree in                      Specimen                                                                           clinging                                                                            Percent de-                                                                         inches at                                                                            Date initi-                                                                          of times                                                                             Chemothera-                                                                          Oct. of fol-                     No.  leaves                                                                              foliation                                                                           breast height)                                                                       ally injected                                                                        injected)                                                                            peutic lowing year                      __________________________________________________________________________    1    35    20    38     June 6 16.8(1)                                                                              Terramycin                                                                           Dead                                                                   70%                                     2    4     1     28.0   June 9 51.8(7)                                                                              Terramycin                                                                           Dead                                                                   70%                                     3    0     1     33.0   June 14                                                                              61.0(8)                                                                              Terramycin                                                                           Dead                                                                   70%                                     4    10    1     34.0   June 14                                                                              53.2(7)                                                                              Terramycin                                                                           Dead                                                                   70%                                     5    0     0     20.0   June 18                                                                              4.2(1) Terramycin                                                                           Dead                                                                   70%                                     E-2  0     0     5.0    Control                                                                              Control                                                                              Control                                                                              Dead                             E-4  0     0     9.0    Control                                                                              Control                                                                              Control                                                                              Healthy                          Ce-1 5     0     36.2   Aug. 13                                                                              5.0(1) KT-198 Healthy                          CE-2 5     0     26.0   Aug. 13                                                                              5.0(1) KT-198 Healthy                          CE-4 10    0     20.6   Aug. 13                                                                              5.0(1) KT-198 Healthy                          CE-5 10    0     39.1   Aug. 13                                                                              5.0(1) KT-198 Healthy                          CE-7 10    0     24.4   Aug. 13                                                                              5.0(1) KT-198 Healthy                          CE-10                                                                              5     0     29.8   Sept. 3                                                                              5.0(1) KT-198 Some decline                                                                  at top                           CE-12                                                                              5     0     27.0   Sept. 3                                                                              5.0(1) Terramycin                                                                           Healthy                                                                70%                                     CE-14                                                                              5     0     32.0   Control                                                                              Control                                                                              Control                                                                              Dead                             CE-15                                                                              5     0     41.0   Sept. 3                                                                              10.0(1)                                                                              KT-198 Healthy                          CE-16                                                                              5     0     17.0   Control                                                                              Control                                                                              Control                                                                              Dead                             CE-18                                                                              3     0     29.7   Sept. 3                                                                              5.0(1) Terramycin                                                                           Considerable                                                           70%    decline                          CE-19                                                                              1     0     31.0   Sept. 3                                                                              5.0(1) KT-198 Marginal                         CE-21                                                                              5     0     21.7   Sept. 6                                                                              5.0(1) KT-198 Healthy                          CE-24                                                                              2     0     24.9   Sept. 6                                                                              5.0(1) KT-198 Healthy                          CE-25                                                                              5     0     21.0   Sept. 6                                                                              10.0(1)                                                                              Terramycin                                                                           Healthy                                                                70%                                     CE-22                                                                              20    5     37.2   Sept. 6                                                                              5.0(1) Terramycin                                                                           Dead                                                                   70%                                     __________________________________________________________________________    Summary                                                                       Treatment Total Number of Trees                                                                     Number Healthy                                                                          Number Marginal                                                                         Number Dead                         __________________________________________________________________________    KT-198    10          8 (80%)   2 (20%)   0 (0%)                              Terramycin 70%                                                                          9           2 (22%)   1 (11%)   6 (67%)                             Control   4           1 (25%)   0 (0%)    3 (75%)                             __________________________________________________________________________

Example C-2

The disease caused by aster yellows on Vinca results in formation ofwitches broom-like growth, with virescent or green flowers. 10 Vincarosea cuttings with severe infection of aster yellows were steeped in a550 ppm solution of KT-198 (about 0.00055%) for three hours and thenplanted: ten other cuttings, serving as controls, were stepped in wateronly and then planted. As positive control, 10 diseased cuttings weresteeped for three hours in 1000 ppm of oxytetracycline hydrochloride.Tetracyclines (Chlor, Oxy and tetracycline hydrochlorides) are the onlychemotherapeutants known for controlling mycoplasma-like diseases (MLO).After a period of 45 days, all the cuttings had rooted. The controlsshowed 100 percent infection. KT-198 treated cuttings showed no diseasesymptoms, and were normal and healthy. Seven of theoxytetracycline-treated cuttings survived, and they were free fromsymptoms, but showed severe etiolation due to phytotoxicity ofoxytetracycline.

Example C-3

Citrus greening and die-back is a severe disease of citrus caused byrickettsia-like organism in the phloem. It is a limiting factor incitrus production in Asia, South America and Australia, though absent inthe United States, where a close relative of this rickettsia causesyoung tree decline of citrus in Florida. The only known treatment so faris injecting tetracycline compounds such as chlortetracycline,oxytetracycline and tetracycline into the stem. The diseased treesrecover, but after several months the disease reappears because thetetracyclines only have static effect and not cidal effect.

The disease symptoms of citrus greening and die-back are veryconspicuous, by the yellowing and drying up of the shoots from the top.Such plants can be easily diagnosed. 100 diseased trees were selectedand divided into four groups of 25 plants each. The treatments were:

(1) KT-198: One gram per tree of KT-198 dissolved in 500 ccs of water(about 0.002%) and injected into the trunk of the tree. Injection wascarried out from a feed bottle serving as tank for the chemical solutionand infused into the stem through a plastic tube into a hole bored inthe stem. In 4 to 8 hours all the solution is taken up by the plant.

(2) Oxytetracycline hydrochloride: 500 ppm in 500 ccs of water.

(3) Tetracycline hydrochloride: 500 ppm solution in 500 ccs of water.

(4) Controls with water only.

The remission of disease symptoms is indicated by the development of newflush green leaves filling up the gap between wilting shoots and by thetree beginning to bear flowers and fruits. This is seen three monthsafter treatment with KT-198. In controls, all the trees remaineddiseased, some of them showing more advanced symptoms. All the KT-198treated trees showed recovery depending upon the severity of the diseasebefore treatment. Tetracyclines were effective in reducing the symptoms,but the plants showed yellowing due to phytotoxicity of tetracyclines.At the end of two years, all the KT-198 treated plants remained healthy.Eight of the oxytetracycline treated, and four of the tetracyclinetreated trees, showed greening and die-back symptoms again.

The above two examples illustrate effective control of both MLO and RLOdiseases, by KT-198 treatment. Several other MLO and RLO diseases havesimilarly been treated and controlled.

Example C-4

Among the plant viruses, soybean yellow mosaic is taken as an examplefor legume virus controlled by KT-198. Diseased seeds, which can beidentified by the brown patch near the hilum, are treated with theglycerine formulation containing 2.5 grams KT-198 in 10 cc (about 25%).The seeds are kept for 12 hours after treatment at room treatment duringwhich time the chemotherapeutant is absorbed within. The treated anduntreated seeds (serving as controls) are planted and observed fordisease symptoms. The yellow mosaic disease of soybean can be discernedwhen the second leaf stage comes up, the diseased plants showing mosaicand crinkling symptoms. Ninety-five percent of the treated seeds becomedisease free, while all the controls show disease symptoms. With a sprayschedule of KT-198 (10 cc in a liter of water which would contain 500ppm of active ingredient), the disease in the afflicted five percent ofthe plants is well controlled.

D. CHEMOTHERAPEUTIC USE OF KT-19827

The following examples illustrate the use of KT-19827 in controllingfungal and bacterial plant diseases. KT-19827 fungicide-bactericide maybe formulated in several ways, as in an agriculturally acceptablenon-toxic solvent, and one of the preferred methods is formulating it incommercial glycerine. One part by weight of the KT-19827 is mixed withtwo parts by volume of glycerine. It forms a homogenous formulation andhas long shelf life.

The following examples illustrate the plant protection activities ofKT-19827.

Example D-1

Dutch elm disease incited by Ceratocytis ulmi is a devastating diseasewhich has not been effectively controlled so far. The disease isvascular, and is transmitted by the elm beetle which carries the sporeload from tree to tree in its breeding cycle. Few expensive chemicalssuch as Lignasan (MBC-hydrochloride) of the Benomyl group, and Arbotect,have only static effect and temporarily halt the disease, but there isno regression of symptoms.

In Minnesota, diseased elm trees in the advanced stage of the diseasewere pressure injected with the KT-19827 solution (50 ml of KT-19827formulation in 10 liters of water). Whereas in very severely diseasedtrees the progression of the disease was arrested, in the moderate andmoderate to severely diseased, the symptoms begin to regress in threeweeks (21 days) with the appearance of new healthy leaves which weregreen and full of vigor.

In other parts of the United States, more than 900 trees have beentreated with a high percentage of protection and even control of thedisease. For a large-sized tree with a stem girth of 60 to 70 inches,six to eight holes are bored along the circumference of the tree atshoulder height. Nipples are inserted, which are all connected togetherby a plastic tube onto a pressure vessel in which 12 to 15 liters of a500 ppm solution of KT-19827 is placed. At 25 psi, the KT-19827 solutionis carried into the tree at the injection points, and within 4 to 24hours (depending upon the weather conditions affecting transpiration andwater-flow within the tree), there is complete uptake of the fungicidesolution. The already infected branches are pruned off, and aninsecticidal spray is given to ward off elm beetles. Observations havebeen recorded over a period of several years, and results showed thatwhere there previously was an annual Dutch elm wilting of 10 to 15percent of trees with or without the use of other chemicals for control,KT-19827 reduced tree losses to less than two percent. After treatmentwith KT-19827, some of the trees marked for cutting down evidencedcontrol of the disease and resumed normal appearance and growth.

KT-19827 thus demonstrates a totally unexpected ability to quicklytranslocate from the original injection situs through the entire tree,from roots to crown leaves. This translocating ability of KT-19827eliminates the necessity of having to girdle the tree at the ground linein order to bring the chemotherapeutic within the root system.

Example D-2

Citrus gummosis, a devastating disease, caused by two Phytophotoraspecies, P. palmivora and P. citrophthora, was controlled by treatingthe diseased trees with 10 gallons of KT-19827 solution (1 percent ofthe formulation in detergent), and the trunk and limbs with heavygummosis were swabbed with a 5 percent solution of KT-19827 formulation.

Example D-3

Gandoerma wilt of coconut, which produces rhizomorph in the soil andgirdles the tree at the collar by irrigating the base and roots of thetree, can be controlled with a 1 percent solution of KT-19827 (10gallons per tree), and injecting one liter of a 1 percent solution inthe trunk.

Example D-4

Powdery mildew of cucurbits, caused by Erysiphe chicoracearum, E,fuligena, powdery mildew of angle (Podosphaera leucotricha), of grapes(uncinula necator), of various ornamentals including roses (Sphaerothecapannosa) are controlled by spraying with a 1 percent solution ofKT-19827.

Example D-5

Downy mildew of grapes (Plasmopara viticola) causes whitish downy growthon the leaves and damping off and rotting of the leaves and fruits. Thedisease may be established in an experimental study by spraying azoospore suspension of the fungus and incubating the inoculated plantsin a humid chamber. For studying the protective effect of KT-19827, 10plants bearing young leaves were sprayed with sporangialzoosporesuspension, and incubated in a moist chamber. Another 10 plants werepreviously sprayed with a 500 ppm solution of KT-19827, and 48 hoursafter, the plants were sprayed with the sporangian-zoospore suspensionand incubated in the moist chamber. Ninety-six hours after, the plantswere taken out and evaluated for disease scoring. None of the KT-19827sprayed plants showed any disease symptoms, while the untreated onesshowed yellowing and rotting of the leaves, and heavy growth of whitesporangial mass of Plasmopara viticola.

Downy mildew of cucurbite (Pseudo-peronospora cubensis), of hops (P.humuli) and others are also controlled by spraying with 1 percentsolution of KT-19827.

Example D-6

Alternaria leaf spots of tomato and potato, Cercospora arachidicola andC. personata on peanuts, and numerous other leaf spots are wellcontrolled by 1 percent spray of KT-19827.

Example D-7

Diseases of lawn, particularly winter killing patches, dollar spot ofKentucky blue grass caused by combined infection by Rhizoctonia-Pythiumspecies and Fusarium niyeale, can be effectively controlled by wateringthe lawn with 500 to 1000 ppm solution of KT-19827 formulation. Not onlyis the disease controlled, but the whole lawn becomes very green as auniform flush-green mat.

Example D-8

Many other leaf spot diseases like coffee rust Hemileia vastatrix, applescab fungus (Venturia inaequalis) and others are amenable for control byspraying with KT-19827 formulation.

Example D-9

Seed treatment with the whole KT-19827 formulation without dilution, inthe dosage range of 0.2 to of 0.5 percent of the seed weight, controlledseed-borne infections of several species of Dreschslera on cerealstested, Septoria species on wheat, Phomopsis and Cercospira kikuchii onsoybeans, Cercospora beticola on sugar beet seeds, Alternaria species onBrassica species, Phoma lingam on cabbage, etc. and other similarseedborne pathogenic dematiaceous fungi.

In addition, Pseudomonas glycinea, a bacterial disease of soybean seeds,and Septoria glycinea, a fungal disease of soybean seeds, are controlledby treating 2.5 lbs. of soybean seeds with 20 cc of KT-19827 incommercial detergent, or in 10 (ten) cc of methanol (methyl alcohol). Onplanting the seeds, the germination was normal, and none of theseedlings showed symptoms of bacterial blight, or Phomopsis blight.There was no carry over of Cercospora kikuchii causing leaf disease norSeptoria blight. For comparison, Benlate (benzamidazole carbamate)fungicide of DuPont was used, which controlled the fungal diseases andnot the bacterial blight.

At present, there are no bactericides available for controlling plantbacterial diseases. The previous use of streptomycin has been abandoneddue to the development of resistant bacterial strains. Benlate (abenzimidezole carbamate of DuPont) controls the fungal diseases but notthe bacterial diseases; KT-19827 offers the first effective control ofbacterial plant pathogens.

Example D-10

Soil-borne Phytophthora species inciting great damage to importantcommercial crops like P. fragariae causing red stele of strawberry, P.cinnamomea on avocado roots, Phytophtora megasperma var. sojae onsoybeans, Phythium aphanidermatum on papaya are controlled by irrigatingthe soil with a 500 ppm solution of the KT-19827 formulation in water.No phytotoxic effect of any kind is noticed in the treated plants.

Example D-11

Bacterial blights of bean are incited by species of Xanthomonas.Xanthomonas phaseoli, X, phaseolicola and Pseudomonas phaseolicola areinternally seed-borne. The pathogen is deep on the embryo. 15 cc of theKT-19827 formulation in commercial detergent, is added to 1 kilogram ofthe seed, thoroughly coating the seeds, and the seeds are planted after12 hours. The fungicide-bactericide penetrates and decontaminates theseed from the pathogen. The seeds germinate normally without anyphytotoxic symptoms, and are healthy.

To prevent field infection from neighboring plots, a foliar spray ofKT-19827 at a concentration of 5 cc per liter (500 ppm activeingredient) protects the plant from foliar infection.

It is apparent that many modifications and variations of this inventionas hereinbefore set forth may be made without departing from the spiritand scope thereof. The specific embodiments described are given by wayof example only, and the invention is limited only by the terms of theappended claims.

The embodiments of the invention in which an exclusive property orpriviledge is claimed are defined as follows:
 1. As a newchemotherapeutic agent, the tannate complex of picro ammonium formatewherein for each 100 parts by dry weight of ammonium formate saidcomplex includes from about 2 to 5 parts by weight of picric acid andabout 0.5 to 2 parts by weight of tannic acid combined with about 2 to10 parts by weight of surfactant sufficient to prevent formation ofammonium picrate.
 2. The complex of claim 1 wherein said surfactant isan alkali metal alkyl sulphate.
 3. The complex of claim 2 wherein saidsurfactant is sodium lauryl sulphate.
 4. The complex of claim 1 whereinthe complex is admixed in amount from about 0.00055 to about 25 percentwith an agriculturally acceptable non-toxic carrier.
 5. A process forthe control of plant diseases caused by mycoplasma-like organisms,rickettsia-like organisms, or seed-borne legume viruses which comprisestreating diseased plants with an effective amount of a tannate complexaccording to claim
 4. 6. A process for the preparation of the complex ofclaim 1 which comprises reacting about 2 to 5 parts by weight of picricacid with 100 parts dry weight ammonium formate already in a viscidaqueous solution containing about 2 to 10 parts by weight of asurfactant in amount sufficient to prevent formation of ammoniumpicrate, and about 0.5 to 2 parts by weight of tannic acid.